Oncoprotein protein kinase

Abstract

An isolated polypeptide (JNK) characterized by having a molecular weight of 46 kD as determined by reducing SDS-PAGE, having serine and threonine kinase activity, phosphorylating the c-Jun N-terminal activation domain and polynucleotide sequences and method of detection of JNK are provided herein. JNK phosphorylates c-Jun N-terminal activation domain which affects gene expression from AP-1 sites.

We claim: 
     
       1. A method for identifying a composition which affects a kinase characterized as having a molecular weight of 55 kD as determined by reducing SDS-PAGE; having serine and threonine kinase activity; and phosphorylating the c-Jun N-terminal activation domain, comprising: a) incubating components comprising the composition and the kinase or polynucleotide encoding the kinase, wherein the incubating is carried out under conditions sufficient to allow the components to interact; and   b) measuring the effect of the composition on the kinase or polynucleotide encoding the kinase.   
     
     
       2. The method of claim 1, wherein the effect is inhibition of the kinase. 
     
     
       3. The method of claim 1, wherein the effect is stimulation of the kinase. 
     
     
       4. The method of claim 1, wherein the composition is an immunosuppressing agent.